I want to thank everyone for all their replies, even if we don't always see eye to eye. This is a great community and a fun, rewarding hobby.
That said, the sound out of the Gumby now has completely toppled my perception of how you're supposed to enjoy music. I will try to explain this the best way I can... basically things sound so realistic, they are less "showy". When you're in a real room with real instruments, sounds are coming at you from across the room... there is oxygen in the room, and room reflections come into play... other DACs I've owned have rendered these sounds in a "showy" manner, meaning it sounds like it has "character", a "look at me!" nature to the sound where everything actually seems louder and more in your face, more in line with headphone listening, where your ears are so close to the drivers, everything seems more flashy.
The Gumby is now completely altering the nature of the way the music is coming out of the drivers. For instance, in an orchestral recording, sounds coming at you (the mics) no longer sound showy, but almost quieter and more subdued, even though they are more striking, realistic and powerful. This sounds like a contradiction, but that's the nature of live sounds... they are sound waves traveling through oxygen to reach your ears, and this is what the Gumby is giving me now. I am having to turn the volume up to get the same impact as I was before, but this actually is a bad idea, as loud sounds are still loud, they just seem less impactful because they are sound waves traveling through oxygen to reach your ears. So it becomes deceptively easy to harm your ears. In this way, I am having to re-adjust my listening habit to take in all the incredible detail without being wowed by the showy nature of the affair. It is music traveling through oxygen to reach my ears, like any live setting and live settings are not like headphone listening.
Another benefit is that albums I thought were badly mastered actually sound incredible. A couple movie score albums (Return of the Jedi, Final Fantasy The Spirits Within) really caught my attention. With my previous DACs (even the Mimby) these albums sounded muffled and indistinct compared to some of the better mastered material. Listening now, there is so much more realism and clarity that it is a whole new (and better) experience listening to them. Again, they just sound REAL, with little to no sense of any mastering process taking place to give the sound any "character". The only character I can discern are the placement of microphones in the room, which is different with every recording. Whereas previously these albums gave a sense of there being something in the way... a shoddy mastering job or something. Not really so anymore. I have not yet explored my really badly mastered junk albums, so I'm not sure how far this phenomenon can go.
I still have a feeling the sound is still settling in though because there is still a kind of hardness/roughness to the sound, that is especially apparent in the treble... it is kind of lacking the smoothness/liquidity that was there before, but it has been a fun eye opening experience letting this DAC warm up.